I would strongly argue against protein crystals (in most cases) being
solid state. Most of the surface of a molecule is actually solvated and
protein crystals as they are miss some of the typical properties of
"solid state". Although in some cases oligomerization occuring upon
protein crystallization indicates fairly strong interactions between
molecules, still the crystals are actually half liquid.
This is the main reason why many ligand exchange and activity studies
could be performed even in protein crystals.
Quite often (I think) protein crystallographers would actually like
their crystals to really behave like solids (stability, localization of
disordered regions, etc.)
no need for cryoprotection and it is hard to make them ...
Jan Dohnalek
IMC Prague
Jayashankar wrote:
> Here we are dealing with two different state of chemistry,
> solid state and solution state, If one of the minima in solid state
> resembles
> the biological state minimum, then there is a possiblw way to clearly
> define
> the biology and its significant interaction of that particular 'mer'
> of a protein, other wise we end
> up with pure physical interaction.
>
> But my question is have we answered Wouldn't the high concentration in
> the crystallization drop further favor dimerization? this part ...
>
>
> S.Jayashankar
> Research Student
> Institute for Biophysical Chemistry
> Hannover Medical School
> Germany.
>
>
> On Thu, Dec 11, 2008 at 5:53 PM, Phoebe Rice <[log in to unmask]
> <mailto:[log in to unmask]>> wrote:
>
> Mass action is on the crystal's side.
> Two recent examples of proteins that are dimers by standard
> solution assays, but form weak/transient/co-factor-dependent
> tetramers to function, and those tetramers are seen in the
> crystal. (There is good solution data to back up the
> relevance of the tetramer in both cases).
>
> Yuan P, Gupta K, Van Duyne GD. Tetrameric structure of a
> serine integrase catalytic domain. Structure. 2008 Aug
> 6;16(8):1275-86.
>
> Mouw KW, Rowland SJ, Gajjar MM, Boocock MR, Stark WM, Rice PA.
> Architecture of a serine recombinase-DNA regulatory complex.
> Mol Cell. 2008 Apr 25;30(2):145-55.
>
> Phoebe
> ==========================================
> ---- Original message ----
> >Date: Thu, 11 Dec 2008 10:09:33 -0600
> >From: "Santarsiero, Bernard D." <[log in to unmask] <mailto:[log in to unmask]>>
> >Subject: [SPAM:#] [ccp4bb] O/T: can a protein which dimerizes
> in solution crystallize as a monomer?
> >To: [log in to unmask] <mailto:[log in to unmask]>
> >
> >In parallel with the discussion around this off-CCP4-topic,
> are they any
> >good examples of the opposite case, where the protein is a
> monomer in
> >solution (as evident from light scattering, MW determination
> through
> >centrifugation, EPR, etc.) but crystallizes as a dimer or
> higher multimer?
> >
> >Bernie Santarsiero
> Phoebe A. Rice
> Assoc. Prof., Dept. of Biochemistry & Molecular Biology
> The University of Chicago
> phone 773 834 1723
> http://bmb.bsd.uchicago.edu/Faculty_and_Research/01_Faculty/01_Faculty_Alphabetically.php?faculty_id=123
>
> RNA is really nifty
> DNA is over fifty
> We have put them
> both in one book
> Please do take a
> really good look
> http://www.rsc.org/shop/books/2008/9780854042722.asp
>
>
--
==============================================
Mr. Jan Dohnalek, Ph.D
Institute of Macromolecular Chemistry
Academy of Sciences of the Czech Republic
Laboratory of Structural Analysis of Molecules
Heyrovskeho nam. 2
16206 Prague 6
Tel: +420 296809390
Fax: +420 296809410
http://protein.awardspace.com/
==============================================
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